4x(y-x)-y②=4xy-4x②-y②=-(2x-y)②3x②-1/3=3(x②-1/9)=3(x+1/3)(x-1/3) (x②+y②)②-4x②y②= (x②-y②)②2x②+2x+1/2=2(x②+x+1/4)=2(x+1/2)② 2a(x②+1)②-2ax②=2a(x^4+x^2+1)(a-b)(3a+b)②+(a+3b)②(b-a)=(a-...